update(entrypoint): exit early on Maven/Gradle project, and

- display warning on auth w/o using token
- proper `sonar-project.properties` link
- unset `JAVA_HOME` environment (fix #31)

entrypoint.sh

@@ -12,9 +12,26 @@ fi
 
 REPOSITORY_NAME=$(basename "${GITHUB_REPOSITORY}")
 
-[[ ! -z ${INPUT_PASSWORD} ]] && SONAR_PASSWORD="${INPUT_PASSWORD}" || SONAR_PASSWORD=""
+if [[ ! -z ${INPUT_PASSWORD} ]]; then
+  echo "::warning ::Running this GitHub Action without authentication token is NOT recommended!"
+  SONAR_PASSWORD="${INPUT_PASSWORD}"
+else
+  SONAR_PASSWORD=""
+fi
 
-if [[ ! -f "${GITHUB_WORKSPACE}/sonar-project.properties" ]]; then
+if [[ -f "${INPUT_PROJECTBASEDIR%/}pom.xml" ]]; then
+  echo "::error file=${INPUT_PROJECTBASEDIR%/}pom.xml::Maven project detected. You should run the goal 'org.sonarsource.scanner.maven:sonar' during build rather than using this GitHub Action."
+  exit 1
+fi
+
+if [[ -f "${INPUT_PROJECTBASEDIR%/}build.gradle" ]]; then
+  echo "::error file=${INPUT_PROJECTBASEDIR%/}build.gradle::Gradle project detected. You should use the SonarQube plugin for Gradle during build rather than using this GitHub Action."
+  exit 1
+fi
+
+unset JAVA_HOME
+
+if [[ ! -f "${INPUT_PROJECTBASEDIR%/}sonar-project.properties" ]]; then
   [[ -z ${INPUT_PROJECTKEY} ]] && SONAR_PROJECTKEY="${REPOSITORY_NAME}" || SONAR_PROJECTKEY="${INPUT_PROJECTKEY}"
   [[ -z ${INPUT_PROJECTNAME} ]] && SONAR_PROJECTNAME="${REPOSITORY_NAME}" || SONAR_PROJECTNAME="${INPUT_PROJECTNAME}"
   [[ -z ${INPUT_PROJECTVERSION} ]] && SONAR_PROJECTVERSION="" || SONAR_PROJECTVERSION="${INPUT_PROJECTVERSION}"
@@ -31,7 +48,6 @@ if [[ ! -f "${GITHUB_WORKSPACE}/sonar-project.properties" ]]; then
 else
   sonar-scanner \
     -Dsonar.host.url=${INPUT_HOST} \
-    -Dsonar.projectBaseDir=${INPUT_PROJECTBASEDIR} \
     -Dsonar.login=${INPUT_LOGIN} \
     -Dsonar.password=${SONAR_PASSWORD}
 fi